This invention relates to an adjustable spray device, particularly one of simple, self-sealing construction.
Several devices are in use for irrigating plants and the like which distribute water in a fan-like spray or jet. They are designed to be attached directly to a manifold pipe or to be supplied with liquid by narrow, flexible tubing attached to the manifold pipe. In contrast to drip irrigation systems, these spray devices typically distribute a larger volume of water over a wide area of soil in a shorter period of time. There is a trend to combine the advantages of spray and drip irrigation systems in a "mini-sprinkler" system for both orchards and the production of container grown stock in nurseries, as well as in landscaping situations. Such systems combine the advantages of savings in water and labor offered by drip irrigation without requiring an expensive and onerous filtration system. Also, the greater volume of water they dispense helps to leach the soil of harmful salt build-ups.
In many situations it is desirable to be able to adjust or vary the volume of irrigating water being delivered from each irrigating device, both because different sizes and types of plants require differing amounts of water and because pressure changes in the manifold, brought about by friction losses or changes in grade, cause differences in the volume of liquid disbursed from device to device within the system. In container nurseries it is often desirable to shut off individual plant watering devices completely when a plant is removed without also shutting off irrigation of the remaining plants. Further, it is frequently advantageous to be able to vary the liquid distribution pattern of the device from a full circle to a narrow arc. Another problem facing installations of spray devices attached directly to a flexible manifold is the tendency for the pipe to twist, distort or move under changes in temperature, pressure or other conditions, with a consequent misdirection of the spray.
The invention herein described is addressed to these problems, providing a device which not only offers many significant advantages over other, previous irrigating devices, but which also is simple in construction and economical to manufacture.